This invention relates to a coil winding method and apparatus. More specifically this invention relates to positioning of a start wire of a wound coil prior to the insertion of the coil into the stator core of a dynamoelectric machine.
Conventionally, the stators of electric motors are manufactured by first providing a slotted core formed of a stack of laminations. Windings or coils are then wound and are subsequently inserted into the slots of the stator core. Quite often more than one set of windings is provided for an electric motor such as for instance a main winding and an auxiliary winding. The auxiliary winding is generally the last winding to be inserted into the stator core. Conventionally, the start wire of the auxiliary winding is located on the bottom of the coil bundle prior to the insertion of the winding into the core slots. Thus, after insertion, the start wire is located closest to the bore side of the stator core. This is not a very desirable location for the start or lead wire as in that position the start wire is quite vulnerable to damage from both the sharp edges of the laminations as well as from subsequent pressing and compressing operations in the windings. Thus it is desired to provide a method and apparatus for relocating or repositioning the start wire, after winding of a coil but prior to insertion of the coil into the stator core. In the prior art such repositioning has been accomplished manually by an operator who manually manipulated the wire from the bottom of the coil bundle to the top of the coil bundle. After insertion into the stator the start wire would then be located between the auxiliary coil and the main coil. Since this is a low density portion of the wire pack, the start wire would then be protected in the subsequent pressing and compressing operations. The disadvantage of the prior art manual method of repositioning the start wire has been that the process is cumbersome, time consuming and therefore costly.
It is therefore desired to provide a method and apparatus for automatically repositioning the start wire of a coil while the coil is being wound, so that, upon subsequent insertion of the coil into a stator core, the start wire is located in a protected location.